论文标题
重新观察NLS1 Galaxy RE J1034+396。 I.长期，复发性X射线QPO，具有很高的意义
Re-observing the NLS1 Galaxy RE J1034+396. I. the Long-term, Recurrent X-ray QPO with a High Significance
论文作者
论文摘要
RE J1034+396是一个狭窄的Seyfert 1 Galaxy（NLS1），其中在2007年观察到了活跃银河系核（AGN）中的第一个重要的X射线准确振荡（QPO）。我们报告了该QPO在2018年XMM-Newton的最新观察中的检测。此QPO的质量因素为20，其周期为3550 $ \ pm $ 80 s，比2007年短250美元$ \ pm $ 100 s。虽然QPO的时期没有显着的能量依赖性，但其分数root-square（rms）可变性从0.3-1 kev中的4％增加到1-4 kev带中的4％。一个有趣的现象是，QPO在0.3-1 keV中的QPO领导，在1-4 keV频段中，$ \ pm $ 50 s $ 50 s具有很高的连贯性，与2007年观察的软X射线滞后相反。我们推测QPO QPO具有内在的硬滞后滞后，而先前报道的软滞后是由Soft Soft Lag引起的。新数据中的这种软X射线引线支持了这样的想法：RE J1034+396的QPO是在黑洞二进制（BHB）GRS 1915+105中看到的67 Hz高频QPO的AGN对应物。我们还搜索QPO谐波，但找不到任何重要信号。我们的新数据增强了以前的结果，即在特定的光谱状态下看到QPO，因为只有2个没有显着QPO信号的2个观测值比显示QPO的其他6个观察值更强的软X射线过量。因此，我们的结果表明，RE J1034+396中的QPO物理上与软X射线组件链接。
RE J1034+396 is a narrow-line Seyfert 1 galaxy (NLS1) in which the first significant X-ray quasi-periodic oscillation (QPO) in an active galactic nuclei (AGN) was observed in 2007. We report the detection of this QPO in a recent XMM-Newton observation in 2018 with an even higher significance. The quality factor of this QPO is 20, and its period is 3550 $\pm$ 80 s, which is 250 $\pm$ 100 s shorter than in 2007. While the QPO's period has no significant energy dependence, its fractional root-mean-square (rms) variability increases from 4% in 0.3-1 keV to 12% in 1-4 keV bands. An interesting phenomenon is that the QPO in 0.3-1 keV leads that in the 1-4 keV bands by 430 $\pm$ 50 s with a high coherence, opposite to the soft X-ray lag reported for the observation in 2007. We speculate that the QPO has an intrinsic hard lag, while the previous reported soft lag is caused by the interference of stochastic variability. This soft X-ray lead in the new data supports the idea that the QPO of RE J1034+396 is a possible AGN counterpart of the 67 Hz high-frequency QPO seen in the black hole binary (BHB) GRS 1915+105. We also search for QPO harmonics, but do not find any significant signals. Our new data reinforce previous results that the QPO is seen in a specific spectral state, as the only 2 observations showing no significant QPO signal exhibit an even stronger soft X-ray excess than the other 6 observations which display the QPO. Therefore, our results imply that the QPO in RE J1034+396 is physically linked to a soft X-ray component.
